Method for recycling synthetic wood materials from sheathing board for use in a concrete form formed by synthetic wood materials, and sheathing board for use in a concrete form having the previously mentioned recycled synthetic wood materials as raw materials

ABSTRACT

There is provided a method for recycling synthetic wood materials, transformed into materials through a relatively simple method without performing elimination of encrusted concrete from a previously used sheathing board for use in a concrete form having synthetic wood materials as raw materials.  
     The method consists of a step wherein a sheathing board  1  ( 1   a ) which had been previously used as a concrete form  50  and formed from synthetic wood materials with a moisture content of less than 15 wt %, wherein between 20 and 75 wt % of cellulose crushed materials, such as wood meal with particle diameters of between 50 and 200 μm, and between 25 and 80 wt % of thermoplastic resin molding materials, are mixed, is crushed into numerous coated particles  82 , and a step wherein a scraping impact force is applied to each individual coated particle  82 , concrete and other encrusted materials encrusted on the previously mentioned coated particles  82  are peeled or separated, and at the same time as the synthetic wood materials constituting the coated particles  82  and the encrusted materials are classified, the particles of the synthetic wood materials are granulated, and the granulated synthetic wood meal materials  83  for which the particles have been granulated are recycled.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for recycling syntheticwood materials from sheathing board for use in a concrete form made ofsynthetic wood materials, and a sheathing board for use in concrete formhaving these recycled synthetic wood materials as raw materials, and atechnique for recycling sheathing board which is as lightweight assheathing boards made of plywood, having an adequate workability andbeing convenient to handle, having a sufficient strength for use as aconcrete form and which can be regenerated by retransforming intomaterials after use.

[0003] 2. Description of the Related Art

[0004] As a general concrete form currently in use, there is the formmade of plywood which uses plywood as the sheathing board. In this formmade of plywood, although labor is expended to improve the finishing ofthe concrete surface, such as coating the surface of sheathing boardwith oil or synthetic resin, a sheathing board made of plywood has arelatively light weight and has considerable workability whentransporting and installing, while at the same time, it has aconsiderable workability such as cutting, and, having an adequate heatretaining property towards concrete, it exhibits an excellent efficacyfor casting concrete in the winter

[0005] Such plywood which forms the sheathing board of the plywood formhas natural wood as raw materials. However, according to the 1987“Forest Products Statistics” by FAO, the gross wood export volume fromthe tropical rain forest region was approximately 7,700 m³, of whichJapan imported 27% as 2,200 m³ of South Sea wood, and 76% of thisimported South Sea wood was consumed as plywood. Such environmentaldestruction has been the cause of problems, such as global warming, dueto the deforestation of the rain forest region which is consumed inlarge quantities in this way. Therefore, the amount of consumption ofnatural wood being used for plywood should be decreased.

[0006] As a result of such a requirement, plywood forms are repeatedlyused several times, in an attempt to realize effective use. However, toreuse a previously used plywood form, a so-called “Surface cleaningoperation” needs to be performed, which consists of removing theconcrete encrusted on the surface of the form with a brush or a spatula.This activity is complex.

[0007] In addition, forms which have been, for example, cut and workedto match the working place, the fragments of these forms, furthermore,among the forms which have been repeatedly used as described previously,those which have exhausted their lives as forms due to chipping anddeformation, can not be regenerated and reused in the same way as, forexample, resin materials are, and are ultimately disposed of. Therefore,from the standpoint of the conservation of the natural environment, theappearance of a sheathing board for use in concrete forms is in demand,obviously usable over several times, and made of materials which arerecyclable by, for example, transforming into materials after theirlives as concrete forms have been exhausted.

[0008] As such sheathing boards made of materials other than plywood,metal forms and forms made of resin exist.

[0009] In the above description, the metal form is considerably morerigid when compared to the plywood form, with only slight chipping anddeformation, and can sustain repeated use. However, this metal form isheavier in comparison to the form made of plywood, and does not allowfor operation with human power in cases such as transport, installationand uninstallation. In addition, workability such as cutting is notadequate and its handling is difficult.

[0010] In addition, the metal form is easily influenced by externaltemperatures, has an inadequate heat retaining property towardsconcrete, and is not as suited as the plywood form to operation in thewinter. Also, the concrete surface may become stained by corrosion.

[0011] In addition, as with the previously described plywood form, inorder to improve the mold releasing property, it needs to be coated withoil or synthetic resin mold release agent. Also, to reuse a metal formonce it has been used as a form, a Surface cleaning operation isnecessary to remove the concrete encrusted on its surface with a brushor a spatula.

[0012] Thus, when compared to the previously described form made ofplywood, the metal form is inconvenient to handle, and does not have thequality of a concrete form replacing the form made of plywood.

[0013] A form made of resin has been proposed as a concrete form whichsolves the shortcomings of the metal form such as the ones describedabove, and replaces the form made of plywood (for example, Kokai No.Hei. 6-88421, Kokai No. Hei. 8-23038).

[0014] This form made of resin has fiber reinforced plastic as rawmaterials, wherein plastic such as polypropylene is reinforced withglass fibers, and strength is added to sustain the pressure producedwhen casting concrete, by placing on one side of the sheathing board,several ribs with a height of approximately 60 mm, parallel to thedirection of the length of the sheathing board.

[0015] This form made of resin is lightweight, has considerableworkability such as cutting, and allows for easy handling, when comparedto the previously described metal form.

[0016] However, cutting this form made of resin, reinforced with, forexample, glass fibers, requires that a chainsaw for plastic be used, andat the same time, in the case of such a processing operation, thescattered glass fibers may adhere to the clothes and the skin,accompanied by severe pain and itching.

[0017] In addition, the opening formed on the sheathing board formounting the separator must be formed monolithically when casting thesheathing board made of resin. Therefore, with this kind of sheathingboard, the degree of freedom for working in the field is low.

[0018] In addition, concerning the previously mentioned sheathing boardmade of resin, since, as previously described, it comprises ribs havinga relatively thick thickness of greater than 60 mm to maintain itsstrength, it is a voluminous item for transportation and storage.

[0019] Further, once the sheathing board has been used as a concreteform, its surface is encrusted with large quantities of exogenousmaterials such as concrete and gravel. To transform the broad intomaterials and regenerate a board, it is necessary to perform theelimination of exogenous materials, by eliminating the encrustedmaterials such as concrete and gravel with a brush and a spatula, and byfurther washing the surface of the form after elimination. A largeamount of labor and expense is expended for this operation, andconstitute the weak points of the recycling and regeneration of thesheathing board.

[0020] In addition, as previously described, when washing sheathingboard, the waste water generated during the washing must be treatedappropriately, which requires an installation and labor.

[0021] Consequently, the object of the present invention, is to solvethe above mentioned shortcomings of the prior art, a further object ofthe present invention is to achieve an effective utilization ofresources as well as an improvement of the natural environment byproviding a method for obtaining raw materials from a transformationinto materials, through a relatively simple method, without eliminating,using a brush and a spatula, encrusted materials such as concrete, whichare encrusted on the surface of a sheathing board, used in a concretecasting operation;, and without washing, and by providing at the sametime, a method for regenerating a sheathing board again from theseobtained raw materials, promote the reuse of sheathing boards, anddecrease the amount of usage of sheathing boards made of plywood havingnatural wood as raw materials.

[0022] In addition, another object of the present invention is toachieve an effective utilization of resources as well as an improvementof the natural environment by providing a sheathing board which is aslightweight as a sheathing board made of plywood, has adequateworkability and is convenient to handle, at the same time havingsufficient strength to be used as a concrete form, which can further beregenerated after use, by transforming again into materials, anddecreasing the amount of usage of sheathing boards made of plywoodhaving natural wood as raw materials.

SUMMARY OF THE INVENTION

[0023] In order to achieve the above mentioned object, the method forrecycling synthetic wood materials of the present invention consists ofa step wherein a sheathing board 1 (1 a), formed from synthetic woodmaterials with a moisture content of less than 15 wt %, wherein between20 and 75 wt % of cellulose crushed materials, such as wood meal withparticle diameters of between 50 and 200 μm, and between 25 and 80 wt %of thermoplastic resin molding materials, are mixed, is used as aconcrete form 50, taking as the processing object this sheathing board 1(1 a) used as the concrete form 50, and crushing this sheathing board 1(1 a) into numerous coated particles 82, and a step wherein a scrapingimpact force is applied to each previously mentioned crushed individualcoated particle 82, concrete and other encrusted materials encrusted onthe previously mentioned coated particles 82 are peeled or separated,and at the same time as the synthetic wood materials constituting thecoated particles 82 and the encrusted materials are classified, theparticles of the synthetic wood materials are granulated, and thesegranulated synthetic wood meal materials 83 for which the particles havebeen granulated are recycled.

[0024] In addition, the sheathing board 1 for use in the concrete form50 of the present invention is formed, as previously described, withsynthetic wood materials as raw materials, recycled from the sheathingboard 1 (1 a) formed from synthetic wood materials previously used asthe concrete form 50, wherein the synthetic wood materials have amoisture content of less than 15 wt % and is a mixture of between 20 and75 wt % of cellulose crushed materials, such as wood meal with particlediameters of between 50 and 200 μm, and between 25 and 80 wt % ofthermoplastic resin molding materials, and with a hollowness of between20 and 70 % created by forming, within the thickness of the board andwith a defined interval, several hollow spaces extending in a specificdirection, and at the same time, with a thickness of the wallsdelimiting the previously mentioned hollow spaces, of greater than 2 mm.

[0025] Further, in the method for recycling the previously describedsynthetic wood materials a further step may be established, wherein thepreviously mentioned recycled granulated synthetic wood meal materials83 are sifted, to eliminate dust such as encrusted materials mixedwithin the granulated synthetic wood meal materials 83.

[0026] In addition, preferably, a step may be established to dry thepreviously mentioned recycled granulated synthetic wood meal materials83 to a moisture content of less than 0.1 wt %

[0027] In addition, the sheathing board for use in a concrete form,having the previously mentioned recycled synthetic wood materials as theraw materials, may be formed as an immaculate sheathing board, with thesynthetic wood materials recycled from the sheathing board, formed froma previously used synthetic wood materials, as the raw materials,wherein the synthetic wood materials have a moisture content of within15 wt % and is a mixture of between 20 and 75 wt % of cellulose crushedmaterials, such as wood meal with particle diameters of between 50 and200 μm, and between 25 and 80 wt % of thermoplastic resin moldingmaterials.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The objects and advantages of the invention will become apparentfrom the following detailed description of preferred embodiments thereofprovided in connection with the accompanying drawings throughout whichlike numerals denote like elements and in which:

[0029]FIG. 1 is an outline illustration schematically showing the stepfrom the recycling of the synthetic wood materials from the previouslyused sheathing board, to the reproduction of the sheathing board fromsaid recycled synthetic wood materials.

[0030]FIG. 2 is a partly sectional view showing an example of finecrushing means (cutter mill) used in the embodiment of the presentinvention.

[0031]FIG. 3 is an overall perspective view showing main parts of themeans for separating, classifying and size regulating of particles(cleaning separator) used in the embodiment of the present invention.

[0032]FIG. 4 is a plan view of FIG. 3.

[0033]FIG. 5 is a partly sectional view taken on line V-V of FIG. 3.

[0034]FIG. 6 is an overall perspective view of the means for separating,classifying and size regulating of particles (cleaning separator), andof each apparatus related to this cleaning separator, used in theembodiment of the present invention.

[0035]FIG. 7 is a front view showing a sheathing board of the presentinvention.

[0036]FIG. 8 is a partial front sectional view of an extruder in theembodiment of the present invention.

[0037]FIG. 9 is a partial plan view of a molding die in the embodimentof the present invention.

[0038]FIG. 10 is a center longitudinal sectional view of a molding diein the embodiment of the present invention.

[0039]FIG. 11 is a perspective view of a molding die in the embodimentof the present invention.

[0040]FIG. 12 is a plan view showing a section of main parts of amolding die in the embodiment of the present invention.

[0041]FIG. 13 is a partly sectional view of a molding die in theembodiment of the present invention molding die.

[0042]FIG. 14 is a partly sectional plan view of a coarsely crushingmeans in the embodiment of the present invention.

[0043]FIG. 15 is a longitudinal sectional view taken on line N-N of FIG.14.

[0044]FIG. 16 is a longitudinal sectional view taken on line J-J of FIG.8.

[0045]FIG. 17 is a longitudinal sectional view taken on line K-K of FIG.8.

[0046]FIG. 18 is a perspective view of a sheathing board of the presentinvention to which shallow wood spacers have been mounted.

[0047]FIG. 19 is a partly sectional view of a concrete form showing anexample of mounting the sheathing board.

[0048]FIG. 20 is a partly sectional view of a concrete form showing anexample of variation of FIG. 19.

[0049]FIG. 21 is an illustration showing an example of assembly usingthe sheathing board of the present invention concrete form, with (A)being a plan view and (B) being a front view.

[0050]FIG. 22 is a perspective view of a sheathing board of the presentinvention to which shallow wood spacers have been mounted.

[0051]FIG. 23 is an illustration showing another example of assemblingthe concrete form using the sheathing board of the present invention,with (A) being a plan view and (B) being a front view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0052] In the following, the embodiment of the present invention will beexplained with reference to the attached figures.

[0053] (Method For Recycling Synthetic Wood Materials)

[0054] The method for recycling synthetic wood materials of the presentinvention, is a method wherein a discarded sheathing board 1 (1 a), madeof synthetic wood materials and used as one part of a concrete form 50,is turned into raw materials, and the latter is retransformed intomaterials to obtain synthetic wood materials. Synthetic wood materialsrecycled through the method of the present invention, can be regeneratedinto, for example, a sheathing board (regenerated product) 1 (1 b) foruse in a concrete form of the present invention, described below.

[0055] Explanation on the method for recycling synthetic wood materialsof the present invention is as follows: this method consists of a stepwherein a discarded and recycled sheathing board 1 a, made of syntheticwood materials, is crushed into coated particles 82 having one side ofbetween 3 and 35 mm (crushing step), a step wherein scraping impactforce is applied to the previously mentioned coated particles 82obtained through the crushing step, concrete and other encrustedmaterials encrusted on the previously mentioned coated particles 82 arepeeled or separated, and at the same time as these resin materials andthese encrusted materials are classified, synthetic wood materials atthe surface of the sheathing board 1 a, deteriorated through itsrepeated use, as well as other coated particles 82 are, for example,slightly trimmed by the application of the scraping impact force, toobtain granulated synthetic wood meal materials 83, which are coatedparticles 82 which have been granulated (step of separation,classification and size regulation), a step wherein the previouslymentioned particular synthetic wood materials 83 obtained through thestep of separation, classification and size regulation, are sifted, andencrusted materials such as dust 84, mixed within the granulatedsynthetic wood meal materials 83, are eliminated (fine classificationstep), a step wherein the previously mentioned granulated synthetic woodmeal material 83 from which dust 84 has been eliminated through the fineclassification step, are dried (drying step), and a step wherein thepreviously mentioned dried granulated synthetic wood meal materials 83are molded into a sheathing board, having a hollow structure, throughmolding with an extruder (molding step) (ref. FIG. 1).

[0056] (Raw Materials)

[0057] The sheathing board 1 a which forms the recycling source for thesynthetic wood materials, has synthetic wood materials as raw materials,formed by mixing wood meal such as cellulose crushed materials, andthermoplastic resin molding materials. As one example, a sheathing board1 a, wherein either or both of the previously mentioned cellulosecrushed materials and thermoplastic resin molding materials whichconstitute the sheathing board 1 a, may have as raw materials variouswaste materials disposed of as construction waste, interior and exteriorequipment for automobiles and vehicles, electric home appliances andpackaging containers, a sheathing board 1 a having as the cellulosecrushed materials construction wastes or wood from roadside trees, whichhave been pruned, disposed of and crushed, and a sheathing board 1 aformed from general thermoplastic resins such as PP, PE, PVC, PET, ABSand PS, as the thermo plastic resin molding materials, may beconsidered.

[0058] Furthermore, the sheathing board 1 a, which forms the recyclingsource for the synthetic wood materials, may be a sheathing boardregenerated with recycled synthetic wood materials as the raw materials,through a method of the invention described below.

[0059] Explanation on the example of production of the sheathing board 1a, which forms the recycling source for the synthetic wood materials, isas follows: the thermoplastic resin molding materials which form the rawmaterials for this sheathing board 1 a, are general thermoplastic resinssuch as PP, PE, PVC, PET, ABS and PS, transformed into materials whichare thermoplastic resin molding materials, either directly, in cases ofpreviously described various articles made of molded resin which havebeen disposed of, or by crushing the articles made of molded resin,having a formed surface resin coating film, into numerous individualparticles, applying compression grinding step to each of the previouslymentioned individual crushed particles to grind and peel the resincoating film, applying compression impact force, which is based onmicrovibrations, to each of the previously mentioned individual groundparticles to collapse and crush them, and eliminating, at any time, theresin coating film peeled by collapsing and crushing.

[0060] In addition, in the extrusion molding, the recycled thermoplasticresin molding materials obtained from the waste of articles made ofthermoplastic synthetic resin, may be reused to charge the previouslymentioned extruder, or a virgin thermoplastic resin may be used forcharging, or a virgin thermoplastic resin and the previously mentionedrecycled thermoplastic resin molding materials may each be used forcharging, for instance at 50% each.

[0061] The cellulose crushed materials which are the other rawmaterials, are crushed to have diameters of particles of between 50 and200 μm (less than 100 mesh), preferably, and after drying to a moisturecontent of less than 15 wt % they are kneaded with thermoplastic resinmolding materials and extruded by the extruder to be molded into asheathing board. In the event that the thermoplastic resin moldingmaterials to be kneaded are PP or PE, the previously mentioned cellulosecrushed materials are included with a proportion relative to the totalamount of kneaded raw materials of 75 wt % maximum, preferably ofbetween 30 and 70 wt %.

[0062] In addition, in the event that the thermoplastic resin moldingmaterial is PVC, wood meal which is cellulose crushed materials is mixedin with a proportion of between 30 to 60 wt %, preferably of 45 wt %,and in the event that the thermoplastic resin molding material is PET,it is mixed in with a proportion of wood meal of 60 wt % maximum,preferably of between 20 and 60 wt %.

[0063] The wood meal, which is cellulose crushed materials, composed aspreviously described, and the thermoplastic resin molding materials, areextruded into a molding die, and are molded as to have a thickness ofbetween 12 and 50 mm, preferably of between 12 and 15 mm, morepreferably of between 16 and 20 mm, a width of between 300 and 900 mm,preferably of between 600 and 900, more preferably of 600 mm, and alength of between 1500 and 2000 mm, preferably of between 1500 and 1800mm, and more preferably of 1800 mm.

[0064] In the event that formation was as an immaculate sheathing board,setting the above mentioned thickness to between 5 and 20 mm, preferablybetween 8 and 15 mm, more preferably between 12 and 14 mm, is suitablefrom the perspective of yield and weight.

[0065] In addition, to further improve the properties of the previouslymentioned wood meal, materials such as wood chips may be immersed inurea resin adhesive, or, after being added to it, may be thermoset,crushed and ground granulated to sizes of between 50 and 200 μm (lessthan 100 mesh). Concerning the method for forming such wood meal,sufficient thermosetting, particularly through thermosetting whileneutralizing with urea resin adhesive, allows the wood acid in the woodmeal, to be rapidly eliminated by neutralization and evaporation, and atthe same time, a hardened adhesive face is established on the wood mealphase, which effectively prevents the increase of moisture within thewood meal, and further increases the slidability of the wood meal, anddecreases the resistance due to friction during extrusion molding.

[0066] In addition, a texture is formed, with an even better intimacybetween the wood meal and the thermoplastic resin molding materials,having a kneaded state which is adequate to decrease the frictionalresistance of wood meal, by charging into a hopper 3 of an extruder 70described below, a synthetic wood powder obtained by mixing together,with stirring impact applying blades, between 20 and 75 wt % ofcellulose crushed materials wherein the moisture content is of within 15wt % and the average diameter of particles is of less than 20 mesh, andbetween 25 and 80 wt % of thermoplastic resin molding materials,kneading the mixture to form gel by friction, air cooling at normaltemperature, or cooling by an appropriate means, the previouslymentioned kneaded materials set to gel, and by further size regulatingthe diameter of particles to less than 10 mm.

[0067] (Crushing Step)

[0068] The present step is a step wherein the previously describedsheathing board 1 a, which is to become raw materials, is crushed intoparticles having one side of between 3 and 35 mm, then these particlesobtained by crushing are recycled as coated particles 82. This crushingstep may form the coated particles 82 by crushing the sheathing board 1a, which is the processing object of the step, into a defined size inone step. However, in the present embodiment, crushing is performedthrough a two stage step of a coarsely crushing step wherein thesheathing board, which is the processing object of the step, is crushedcoarsely, and a fine crushing step wherein the sheathing board particles81, formed by crushing coarsely, are further finely crushed to formcoated particles 82.

[0069] In the present embodiment, through the previously mentionedcoarsely crushing step, the processing object may be crushed in toparticles 81 of undefined form having sides of approximately 20×50 mm,such as, for example, a mixture of squares, rectangles and the like,trapezoids, triangles or other polygons, and the particles 81 obtainedthrough this step are further crushed into particles having a side ofbetween 3 and 35 mm, preferably of between 5 and 20 mm, through a finecrushing step to obtain the coated particles 82.

[0070] In this way, with the present embodiment, by performing acrushing step through 2 or more steps, even for a relatively large 1800mm long, 600 mm wide and 18 mm thick sheathing board, its crushing canbe performed efficiently.

[0071] In addition, this crushing step may also be performed using anyapparatus capable of crushing the sheathing board, which is theprocessing object, into the previously described size In addition, thecrushing step may be performed through a crushing means formed bycombining crushers of the same type or of different types. As oneexample, the present embodiment performs this crushing through acoarsely crushing step performed by a two shaft crusher (crusher 110:ref. FIG. 1), which is a coarsely crushing means, and a fine crushingstep performed by a one shaft crusher (cutter mill 120), shown in FIG.2, which is a fine crushing means. Therefore, in the present embodiment,the crushing step includes the two steps of coarsely crushing step andfine crushing step. In addition, the crushing means is configured bycombining the previously mentioned two shaft crusher and one shaftcrusher.

[0072] (1) Two Shaft Crusher

[0073] As the two shaft crusher used in the previously mentionedcoarsely crushing step, for example, the gainax crusher made by HoraiCo., Ltd., the roll crusher made by Nara Machinery Co., Ltd., andvarious known monocutters, shredders, crushers and the likes (in thefollowing, these will be collectively called “crushers”) may be used.

[0074] This crusher 110, shown in FIG. 1 as one example, is equippedwith two parallel shafts which mutually rotate at the same time towardsthe inside of the crusher body, with several rotating knives placed at aspecific interval on each shaft, and it is equipped to cut coatedgranules into crushed pieces which consist of fragments of suitablesize, with 3 nails protruding from the peripheral face of each rotatingknife so as to form isometric angles, with each shaft being engaged withthe other at the periphery of each rotating knife.

[0075] The coated granules are charged from the charging port of theupper portion of the crusher, pulled inside by the nails of the rotatingknives from the two shafts which rotate mutually inwards, while beingslit by the shearing force applied continuously between the edges at theperiphery of the rotating knives which rotate in an engaged state, andare then crushed and cut by the pressure applied when pulling in, toform crushed pieces. In the present embodiment, the sizes of thepreviously mentioned nails and edges are selected in such a way that thesheathing board, which is the processing object, is crushed coarselyinto approximately 2×50 mm portions, the crushed pieces formed bycrushing the processing object into the previously mentioned size, passthrough the screen installed under the previously mentioned rotatingknives from the two shafts, and are discharged from discharge port. Inaddition, chips 81 formed in this way are crushed coarsely into thechips 81 of undefined shape such as polygon forms such as rectangles andsquares, triangles, trapezoids and rhomboids, and are discharged fromthe previously mentioned discharge port.

[0076] (2) One Shaft Crusher

[0077] The chips 81 crushed coarsely as above are crushed into chipshaving, as one example, a size wherein a side is between 3 and 35 mm,through a known crushing means which is, for example in the presentembodiment, the one shaft crusher (for convenience, called “cutter mill”in the present description), and this constitutes the coated particles82.

[0078] A cutter mill, which is one example of crushing means, is shownin FIG. 2. Numeral 121 is a cutter mill main body, which is a casingforming a cylindrical shape having a charging port 123 on the upperside. Inside the previously mentioned cutter mill main body 121, acutter supporter 124 is installed, which rotates in the verticaldirection via a rotation driving means not shown, and whose axis isborne in the cutter mill main body 121. At the periphery of this cuttersupporter 124, 4 (four) long rotating knives 125 are installed in thehorizontal direction so as to form isometric angles of 90 degrees aroundthe direction of rotation of the cutter supporter 124. The tips of theblades of these 4 rotating knives 125 are positioned on the samerotation locus.

[0079] In addition, through a slight interval with respect to the locusof the tips of the blades of the previously mentioned 4 rotating knives125, 2 (two) fixed knives 126 are fixed to the cutter mill main body121, at a position approximately symmetric to the locus of the tips ofthe blades of the rotating knives 125, the interior of the cutter millmain body 121 is divided by the 2 fixed knives 126, the cutter supporter124 and the rotating knives 125, to form a charging chamber 127 and acrushing chamber 128. The previously mentioned charging port 123communicates with the previously mentioned charging chamber 127. Inaddition, the clearance between the 2 fixed knives 126 and the rotatingknives 125 can be freely adjusted to cut the coated granules to adesired size, or generally to crush.

[0080] In addition, the crushing chamber 128 is delimited by a meshscreen 129 in such a way such as to surround the periphery of therotation locus of the rotating knives 125 of the 2 fixed knives 126previously mentioned. In addition, in the present embodiment, the screen129 uses punched metal in which numerous holes with diameters of between5 and 20 are formed. In addition, below the crushing chamber 128, adischarge port 139 is installed for discharging crushed pieces andencrusted materials, such as concrete, which were peeled from thesurface of the chips 81 during crushing, that passed through the screen129.

[0081] In the above cutter mill 120, the chips 81, which were formed bycrushing coarsely with the previously mentioned crusher 110, are chargedfrom the charging port 123, and then, by rotating the cutter supporter124 at, as one example, 800 min⁻¹ by a rotation driving means (power of5.5 KW) not shown, the chips 81, which were formed by crushing coarsely,are crushed coarsely between the rotating knives 125 of the cuttersupporter 124 and the fixed knives 126, into chips of undefined shapesuch as, polygons such as rectangles and squares, or triangles,trapezoids, or rhomboids, with unspecified form and surface. By usingpunched metal having a diameter of between 5 and 20 mm as the screen129, at the same time, by suitably adjusting the operation time, thecharged chips 81 become the coated particles 82 with a size having alength or a diameter of between 3 and 35 mm. These coated particles 82do not pass through the screen 129, and remain inside the crushingchamber 128.

[0082] On the other hand, a portion of the encrusted material such asconcrete which is peeled from the surface of the chips 81 during thepreviously mentioned crushing, and the chips which are crushed to a sizewhich enables them to pass through the opening of the previouslymentioned screen 129, pass through the screen 129 and are dischargedthrough the discharge port 139.

[0083] In this way, the chips which remain inside the crushing chamber128 without passing through the screen, become the coated particles 82.

[0084] In addition, the reason for setting the size of the coatedparticles 82, which are to be brought to the next step, as previouslydescribed to between 3 and 35 mm, lies in the fact that, on one hand, ifone side of the coated particles 82 is less than 3 mm, they are finelycrushed during the step of separation, classification and sizeregulation described below, which decreases the amount of synthetic woodmaterials which is recycled as regeneratable materials, while on theother hand, if it is set to greater than 35 mm, the processing capacityof the step of separation, classification and size regulation isdecreased.

[0085] In addition, in the embodiment shown in FIG. 2, the cutter mill120 is represented as being equipped with a rotation shaft oriented inthe horizontal direction. However, the cutter mill 120 used in thepresent invention may be a cutter mill having a rotation shaft orientedin the vertical direction, and any other types of cutter mill may beused. In addition, any apparatus, other than the cutter mill 120, may beused, as long as it is capable of processing the chips 81 into coatedparticles with defined size.

[0086] (Steps of Separation, Classification and Size Regulation)

[0087] Scraping impact force is applied to the coated particles 82,formed in the crushing step as indicated above by crushing the sheathingboard 1 a, which was used as a concrete form 50, into undefined formshaving one side of between approximately 3 and 35 mm, concrete stillencrusted to the surface of the coated particles 82, and other encrustedmaterials are peeled or eliminated, and at the same time, synthetic woodmaterials are recovered, such as the synthetic wood materialsdeteriorated by repeated usage such as the region corresponding to thesurface of the sheathing board 1 a, by applying the previously mentionedscraping impact force, to slightly trim the coated particles 82themselves so as to regulate and transform them into raw materials.

[0088] An example of configuration of the means for separating,classifying and size regulating of particles used in the presentinvention (for convenience, called “cleaning separator” in the presentembodiment) is shown in FIGS. 3 through 5.

[0089] First, explanation will be given for the outline of the entiretyof a cleaning separator 130: the cleaning separator 130 is equipped witha supply charging port 132 for charging with each of the coatedparticles 82, a collection port 153 for collection of synthetic woodmaterials from which encrusted materials, such as concrete stillencrusted to the coated particles 82, have been peeled and eliminated bytreating the coated particles 82 inside the cleaning separator 130, anda discharge port 152 to discharge encrusted materials peeled from thepreviously mentioned coated particles 82, and dust and the likegenerated by trimming the coated particles 82 themselves by applyingscraping impact force.

[0090] The coated particles 82 processed through the previouslymentioned crushing step are supplied to the previously mentioned supplycharging port 132. The previously mentioned collection port 153communicates with the supply charging port 132 via a communicating pipe235. Piping 236 communicates with the collection port side of thecommunicating pipe 235, from a compressed air supply source not shown. Aflow regulating plate is installed at the communication site with thispiping 236, and is configured to allow mainly compressed air to flow tothe supply charging port 132. In addition, the communicating pipe 235 isbranched, and a branch pipe 237 is installed for transferring to arecovery tank 240 to recover granulated synthetic wood materials 83. Atthe branch point of this branch pipe 237, for example, a three wayelectromagnetic valve 238 is installed, which can be switched atadequately set times using a timer circuit.

[0091] On the other hand, the previously mentioned discharge port 152 iscommunicating with a collecting tank 250 through a discharge pipe 239,and is configured in such a way that dust 84 consisting of, for example,encrusted materials crushed and transformed into fine powders, andpowders of synthetic wood materials generated by trimming the coatedparticles 82 themselves, is discharged from the discharge port 152, isaspirated into the discharge pipe 239, to which a blower 157 isseparately installed, and recovered in the collecting tank 250.

[0092] In FIGS. 3 to 5, explanation on a cleaning separator 130 is asfollows: the cleaning separator 130 used in the present embodiment is asmall type experimental apparatus, and has a processing capacity of 160kg/h for the previously described coated particles 82.

[0093] The previously described supply charging port 132 of thiscleaning separator 130, is connected to, and opens into, the centralportion of a fixed disk 131 having a diameter of 400 mm, a fixedterminal plate 133 closes the processing space 155 and faces thepreviously mentioned fixed disk 131, and the respective peripheral outeredges of the previously mentioned fixed disk 131 and of the fixedterminal plate 133 are fixed with a peripheral plate 135.

[0094] In the previously mentioned processing space 155, the fixedterminal plate 133, and a mobile disk 141 having approximately the samediameter as the fixed terminal plate 133 are installed, the mobile diskbeing driven into rotation by a horizontal rotation shaft 142, and thehorizontal rotation shaft 142 being supported by each bearing 143 and143. The previously mentioned horizontal rotation shaft 142 is driveninto rotation by a rotation driving means such as a motor 161, which, inthe present embodiment, as one example, is rotated at 750 min⁻¹.

[0095] Then, each fixed pin 134 is sequentially planted onto thepreviously mentioned fixed disk 131 at several rotation loci a1-a6 (FIG.5) which are concentric (relatively to the corresponding mobile disk141). On the other hand, each mobile pin 144, distinct from each of thepreviously mentioned fixed pins 134, is sequentially planted onto thepreviously mentioned mobile disk 141 at several rotation loci b1-b6,inserted alternately between the rotation loci of each of the previouslymentioned fixed pins 134. This arrangement makes it possible to obtain astep wherein encrusted materials such as concrete encrusted on thesurface of coated particles 82 are peeled or separated, and a stepwherein coated particles 82 are granulated into spheres, by the scrapingimpact force between each of these fixed and mobile pins 134 and 144.

[0096] More specifically, the number of fixed pins 134 is 16 at therotation locus a1, which is close to the central portion of the fixeddisk 131, and 24 are planted at the rotation locus a2, which is situatedat the periphery of the previously mentioned rotation locus a1.

[0097] On the other hand, the number of fixed pins 144 is 4 at therotation locus b1, which is close to the central portion of the mobiledisk 141, and 4 are planted at the rotation locus b2, which is situatedat the periphery of the previously mentioned rotation locus b1.

[0098] In actuality, enlarging the clearance between each of thepreviously mentioned fixed and mobile pins 134 and 144 weakens thescraping force applied on the coated particles 82, and reducing theclearance strengthens the scraping force.

[0099] In addition, in FIG. 3, on the peripheral outer side of themobile disk 141 and on the peripheral inner side of the previouslymentioned peripheral plate 135, a specific mesh screen 151, in whichpores have been punched, is installed peripherally, closing adischarging space 156, and a discharge port 152 is installed below thedischarging space 156. In addition, in the present embodiment, thepreviously mentioned screen 151 is a mesh having, as one example, poreswith a diameter of 1.2 mm.

[0100] In addition, a collection port 153 is installed at the lower partinside the screen 151 of the processing space 155. This collection port153, as previously described, is communicating with the supply chargingport 132 through a communicating pipe 235, and is communicating with therecovery tank 240 for recycling the recycled granulated synthetic woodmaterials 83, through a branch pipe 237 which branches the supplycharging port side of the communicating pipe 235. In addition, asanother example, a plug valve for controlling opening and closing may beinstalled on the previously mentioned collection port 153, and thecollection port 153 may be connected to the supply charging port 132through a blower 158 which aspirates the air inside the cleaningseparator 130, as shown in FIG. 1.

[0101] Therefore, in the above mentioned cleaning separator 130, wheneach coated particle 82 is supplied to the supply charging port 132 byrotating the mobile disk 141 with the horizontal rotation shaft 142which is rotated by the rotation driving means of the motor 161, eachcoated particle 82 is at the central portion of the processing space155, and each coated particle 82 is struck by the scraping impact forcebetween each of the fixed and mobile pins 134 and 144 and by the impactsfrom each of the fixed and mobile pins 134 and 144, and in addition, byrubbing each of the pins 134 and 144 against the surfaces of the coatedparticles 82, or by rubbing the surfaces of the coated particles 82against each other, the surfaces of the coated particles 82 are scrapedin such way that encrusted materials, as well as deteriorated syntheticwood materials which are encrusted on the surfaces, are finely crushedinto dust form, and are peeled from the surfaces of the particles 82. Inaddition, by the application of this scraping impact force, a portion ofthe surfaces of the coated particles 82 themselves are trimmed and transformed into powder from, and at the same time as being peeled togetherwith encrusted materials, they are granulated into approximatelyspherical forms, and form the granulated synthetic wood meal materials.The encrusted materials peeled from the previously mentioned coatedparticles 82 and the dust 84 generated by trimming the coated particles82 as described above, pass through the screen 151 under the centrifugalaction of each mobile pin 144, are classified into the discharging space156, and from the discharge port 152 and through the blower 157 (FIG. 6)they are then aspirated and discharged to the exterior.

[0102] In addition, in the present embodiment, encrusted materialspeeled from the previously mentioned coated particles 82, and syntheticwood materials in dust form generated by trimming the coated particles82 themselves, are aspirated together with the air inside the cleaningseparator 130, at 15 kw, 460 mm Aq pressure and 65 m³/minute aspirationspeed for large machines, at 3.7 kw, 460 mm Aq pressure and 51 m³/minuteaspiration speed for medium machines, and at 1.5 kw, 400 mm Aq pressureand 3.4 m³/minute aspiration speed for small machines, as the previouslymentioned blower 157.

[0103] On the other hand, coated particles 82 of sizes which do not passthrough the screen 151 accumulate inside the screen 151. Coatedparticles 82 with encrusted materials still encrusted on their surfacesare mixed among the coated particles 82 from which these encrustedmaterials have been eliminated. However, since the collection port 153and the supply charging port 132 communicate with each other through thecommunicating pipe 235, the coated particles 82 extracted from thecollection port 153 flow back to the supply charging port 132,repeatedly scraped in the cleaning separator 130 by receiving scrapingimpact forces again, encrusted materials such as concrete, encrusted onthe surfaces of the coated particles 82 are peeled from the coatedparticles 82, and only the synthetic wood materials constituting thecoated particles 82 remain.

[0104] Although the coated particles 82, from which encrusted materialshave been eliminated as described above, flow back, the majority remaininside the screen 151 without being scraped up to a point so as to passthrough the screen 151. The above step of separation, classification andsize regulation can be reiterated several times as needed until theencrusted materials of the coated particles 82 within one batch areseparated.

[0105] By driving the above cleaning separator 130 with the motor 161,opening the downstream side with a three way electromagnetic valve 238and closing the side of the previously mentioned branch pipe 237, of thepreviously mentioned communicating pipe 235, and by providing compressedair from piping 236 to the communicating pipe 235, an air flow isgenerated by the compressed air, circulating from the communicating pipe235 to the supply charging port 132, the processing space 155, thecollection port 153, and the communicating pipe 235, successively. Wheneach coated particle 82 within one batch is supplied through the supplypipe 231 to the supply charging port 132, at the same time as the coatedparticles 82 are granulated into approximately spherical forms by thescraping impact forces applied to the coated particles 82, powdersformed by finely crushing encrusted materials which are peeled from thesurface of the coated particles 82 by the processing inside the cleaningseparator 130, and the dust 84 formed from synthetic wood materials orthe like generated by trimming one portion of the coated particles 82themselves, said powders and dust pass through the screen 151 and aredischarged to the collecting tank 250 by the blower 157, on the otherhand, the coated particles 82 remaining inside the screen 151 areaspirated into the communicating pipe 235 by the circulating air flowand are again fed into the processing space 155, processed inside thecleaning separator 130, and this suite of step is repeated over severaltimes as needed until the encrusted materials on the surfaces of thecoated particles 82 of one batch are peeled.

[0106] Then, after the above mentioned processing is complete, byclosing the downstream side of the communicating pipe 235 with the threeway electromagnetic valve 238 and by opening the side of the previouslymentioned branch pipe, the granulated synthetic wood meal materialsremaining inside the screen 151, and formed by size regulating thecoated particles 82 which traveled from the communicating pipe 235through the branch pipe 237 into approximately spherical forms, arerecycled in the recovery tank 240.

[0107] Furthermore, as an alternative to the above mentioned three wayelectromagnetic valve 238, an electromagnetic valve which opens andcloses the previously mentioned branch pipe 237 and an electromagneticvalve which opens and closes the down stream side of the previouslymentioned communicating pipe 235 may be installed, and set up so thatthese two electromagnetic valves to open and close alternately.

[0108] (Fine Classification Step)

[0109] In the previously mentioned step of separation, classificationand size regulation, encrusted materials such as concrete encrusted onthe coated particles are peeled from the surface of the coatedparticles, and at the same time are classified from the synthetic woodmaterials crushed and granulated into approximately spherical forms bythe scraping impact forces applied in the previously mentioned step.However, in the event that dust 84 of encrusted materials and the likegenerated by crushing with these scraping impact forces is notcompletely recycled in the preceding step, and dust 84 exists stillmixed among the granulated synthetic wood meal materials 83, theserecycled granulated synthetic wood meal materials 83 are sifted througha sieve 100 of the present step, and the dust 84 mixed among thegranulated synthetic wood meal materials 83 is eliminated.

[0110] The sieve 100 used in the present step may have anyconfiguration, provided it can eliminate fine powder of encrustedmaterials mixed among the granulated synthetic wood meal materials, aspreviously described, and various conventional sieves may be used. Asone example, in the present embodiment, a vibratory sieve (Sato modelvibratory sieve made by Mie Industry Co., Ltd.) is used as this sieve100.

[0111] In addition, in the present step, a sieve equipped with a screenhaving a grid spacing of between 1 to 5 mm, preferably of between 2 to 4mm, and actually of 3 mm in the present embodiment, is used.

[0112] In this way, the granulated particle resin materials 83 recycledthrough the previously mentioned step of separation, classification andsize regulation, are sifted through the sieve 100 of the present step,such that dust of encrusted materials and synthetic wood materials,which passed through the screen, are eliminated, and the granulatedsynthetic wood meal materials, which did not pass through the screen andremained above the sieve, are recycled as regeneration materials forsheathing boards.

[0113] (Drying Step)

[0114] The present step is a step wherein the granulated synthetic woodmeal materials 83, recycled as regeneration materials through thepreviously mentioned fine classification step, are dried to a moisturecontent of less than 0.1 wt %.

[0115] This is because the sheathing board 1 a of the present inventioncontains an important amount of cellulose crushed materials such as woodmeal, and there are cases where moisture is absorbed when used as theconcrete form 50, or during storage, and when the granulated syntheticwood meal materials 83 which have been granulated in a condition whereinmoisture has been absorbed in this way are directly used as regenerationmaterials, regeneration of the sheathing board 1 b can not be performedoptimally.

[0116] This drying step is performed using a conventional dryer 102, andin the present embodiment, a dryer made by Matsui MFG Co., Ltd. is usedas this dryer 102. If the granulated synthetic wood meal materialsrecycled in the previously described way, are dried in this dryer f orapproximately I hour at a temperature of, in the present embodiment, 90°C., the granulated synthetic wood meal materials 83 with a moisturecontent of approximately 1.8 wt % before processing is dried to amoisture content of less than 0.1 wt %, and become adequate asregeneration materials for the sheathing board 1 b.

[0117] In addition, the previously mentioned drying temperature was setto 90° C. in the present embodiment, since the granulated synthetic woodmeal materials 83 melt when drying the granulated synthetic wood mealmaterials 83 at a temperature of greater than 90° C., and, whenperforming drying at lower temperatures, processing by the present steprequires a longer time. In addition, if the moisture content of thegranulated synthetic wood meal materials 83 after drying is greater than0.1 wt %, the quality of the regenerated sheathing board decreases.However, for those materials which can dry to a lower moisture contentthan previously described, the previously mentioned drying temperature,the processing time and the like, can be suitably changed according tothe type of resin constituting the granulated synthetic wood mealmaterials 83 which is the processing object, and other variousconditions.

[0118] In addition, in the apparatus indicated in the above mentionedembodiment, 211 kg (including encrusted materials) of previously usedrecycled sheathing board was processed, and 117.4 kg of dried granulatedsynthetic wood meal materials could be obtained. This recycledgranulated synthetic wood meal material was 55.6% of the weight(including encrusted materials) of the sheathing board transformed intoraw materials, and the synthetic wood materials could be recycled with ahigh recycling rate.

[0119] (Molding Step)

[0120] The granulated synthetic wood meal material 83, recycled anddried in the above described way, is regenerated again into, as oneexample, the sheathing board 1 b for use in a concrete form, eitherdirectly, or mixed with thermoplastic resin materials, which are eithervirgin or disposed of and recycled, and cellulose crushed materials, thesynthetic wood materials having a moisture content of within 15 wt %,wherein between 20 and 75 wt % of cellulose crushed materials, such aswood meal with particle diameters of between 50 and 200 μm, and between25 and 80 wt % of thermoplastic resin molding materials, are mixed.

[0121] In FIG. 7, numeral 1 is a sheathing board for use in a concreteform of the present invention, fabricated with the previously mentionedrecycled synthetic wood materials as raw materials. This sheathing board1 is a sheathing board having the granulated synthetic wood mealmaterials 83 recycled in the previously described way as moldingmaterials, and formed by molding this granulated synthetic wood mealmaterials 83 through extrusion molding to form hollow chambers withinthe thickness of the board.

[0122] The granulated synthetic wood meal materials 83 recycled in thepreviously described way, while being heated and kneaded by an extruder,are extruded into a molding die, and are molded so as to have athickness of between 12 and 50 mm, preferably of between 12 and 15 mm,more preferably of between 16 and 20 mm, a width of between 300 and 900mm, preferably of between 600 and 900, more preferably of 600 mm, and alength of between 1500 and 2000 mm, preferably of between 1500 and 1800mm, and more preferably of 1800 mm.

[0123] In the previously mentioned sheathing board 1, several hollowchambers 2 are formed in the direction of its length, and the previouslymentioned hollow space is formed in such a way such that the thicknessof each wall delimiting these hollow chambers 2 is at least greater than2 mm, preferably between 3 mm and 6 mm, and the hollowness is between 20and 70%. In addition, here, the hollowness is the proportion of thevolume of the hollow chambers 2 with respect to the total volume of thesheathing board comprising the hollow chambers 2.

[0124] (Extruder)

[0125] In FIG. 8, numeral 70 is a single shaft extruder. However, ingeneral, an extruder is of screw type, available as a single shaftextruder or a multiple shaft extruder; and it is available having astructure which is a variation of these or a combination of these, andany of these extruders may be used for the present invention.

[0126] Numeral 71 is a screw of single shaft type. This screw 71 isdriven through a speed reduction gear 72 by a motor not shown, androtates inside a barrel 74. The granulated synthetic wood meal materials83 charged from a hopper 73 are kneaded by this screw 71 in rotation andare extruded to the front of the screw 71. A band heater 75 is installedon the outer surface of the barrel 74, and the granulated synthetic woodmeal materials 83 inside the barrel 74 are heated by this band heater75, while being gradually melted and kneaded along the groove of thescrew 71 and conveyed to the front. Then, through a screen 76 and anadapter 17, the kneaded materials are extruded, as an extrudingmaterials 79, from an extruding die 19 of the adapter 17 to a moldingdie 10.

[0127] (Extruding Die)

[0128] In FIG. 8, the extruding die 19 at the front end of the barrel74, forms an elongated rectangular shape equipped with an ejection port50 mm wide and 18 mm high, which has a front end formed with a thicknessof 8 mm (see FIG. 17). On the inside, a communicating hole is formed,wherein the cross section changes gradually from an inflow port 18 ofthe rear end face of the adapter 17 having a diameter of 50 mm, to theejection port of the previously mentioned extruding die 19. In addition,it is preferable that the inflow port 18 is formed with the same size asthe circular cross section of the ejection port of the extruder 70,while on the other hand it is preferable that the width of therectangular shape of the extrusion die 19 is formed with the same sizeas the diameter of the inflow port 18, and its height is formed with thesame size as the height of a molding chamber 22 of the molding die 10described later.

[0129] In addition, the adapter 17 and the extruding die 19 may beformed in various sizes according to the size of the extruder 70. Forexample, if the diameter of the inflow is 150 mm, the width of therectangle of the extruding die 19 may be of 150 mm and the height may bethe same as the height of the molding chamber 22, which is of 18 mm.

[0130] The inflow port 18 of the adapter 17 and the screen portion ofthe extruder 70 communicate by connecting the rear end of the previouslymentioned adapter 17, through a fixture interlocked at the outerperiphery of said adapter, to the front end face of the screen portionequipped with a screen 76 (FIG. 8) of the extruder 70, with fastenerssuch as bolts. On the other hand, the extruding die 19 and the lead-inportion 11 of a molding die 10 communicate by mounting the front end ofthe ejection port having a rectangular cross section, of the front endof the extruding die 19, onto the lead-in portion 11 having arectangular cross section formed at an approximately central position ofthe rear end of the molding die 10.

[0131] In addition, a heater serving as a heating means may be buriedinside the surrounding wall of the communicating hole of the previouslymentioned adapter 17. In this case, the extruded materials 79, extrudedfrom the outlet of the screen portion 16 of the extruder 70, flow infrom the inflow port 18 of the adapter 17, while being heated andmaintained at temperature by the heater, and flow through thecommunicating hole from the extruding die 19 into the lead in portion 11of the molding die 10. Such a flowing state of the extruded materials 79is excellent. In addition, the previously mentioned extruding die 19differs from a typical general die, having a large ejection portallowing for a large amount of melted raw materials (synthetic woodmeal) to be delivered, and moreover, it is formed into a shape whereinpromoting compaction becomes possible, which means that clogging of thedie as was occurring with a typical die does not occur.

[0132] (Molding Die)

[0133] In FIG. 9 to FIG. 12, numeral 10 is a molding die, and consistsof a lead-in portion 11 which pushes out the extruded materials 79delivered from the ejection port of the extruding die 19 having arectangular cross section, of the extruder 70, and a molding chamberwhich molds the extruded materials 79 pushed out from the lead inportion 11 into a board form having a wide width and a specificthickness, in the present embodiment, a molding chamber 22 forming anelongated rectangular cross section with a width of 600 mm and a heightof 18 mm.

[0134] Numeral 11 is the lead-in portion, formed inside the molding die10, in the direction of the width of the molding die 10, formed with awidth approximately equal to or slightly larger than the previouslymentioned extruder die 19. The shape of the horizontal cross section isformed into a so called coat hanger type wherein both edges of the leadin chamber 13, which extend by curving towards the direction of thewidth of the molding die 10, reach both edges of the long direction ofthe molding chamber 22.

[0135] In addition, although the previously mentioned lead-in chamber 13may be formed into a straight manifold type, in addition to the coathanger type, the previously described curved shape coat hanger type ispreferred, owing to the excellent fluidity of the extruded materials 79flowing inside the lead in portion 11 and the lead in chamber 13.

[0136] In addition, a sheet 24 formed with fluororesin described lateris preferably affixed on the previously mentioned lead in portion 11 andthe lead in chamber 13.

[0137] In addition, the previously mentioned molding chamber 22 isformed into a square cross section by metal spacers, not shown, whereintwo metal plates, one upper and one lower, having a heating and acooling means, are placed at the border of both sides, and adjustmentsmay be made by exchanging the previously mentioned spacers, to obtainany target thickness for the hollow resin molded board.

[0138] The molding die 10 has, as one example, an elongated rectangularcross section with a width of 600 mm and a height of 18 mm, and adistance from the inlet of the molding chamber 22 to the die outlet 23(the distance in the direction of pushing out) of 1,000 mm.

[0139] (Constructions Inside the Molding Die)

[0140] On the inner wall surfaces in the four directions that are above,below, to the right and to the left of the previously mentioned moldingchamber 22, the sheet 24 made of fluororesin and 0.25 mm thick isaffixed. Alternatively, it is possible to directly coat the inner wallsurfaces in the four directions that are above, below, to the right andto left of the molding chamber 22 with fluororesin, but it isparticularly preferable to affix fluororesin sheets 24, considering thepoints that their replacement is easy, the step of coating them withfluororesin is easy, and their durability is excellent.

[0141] Particularly preferably, the previously mentioned sheet 24 is asheet made of glass woven fabric with a film of fluororesin coated onits surface. As described above, teflon TFT, teflon FEP, teflon CTFE,teflon Vdf or the like, are available as fluororesin. In addition, thepreviously mentioned glass woven fabric may be a non woven fabric ofglass fibers.

[0142] In addition, the previously described step of coating withfluororesin may be performed on the upper and lower inner surfaces ofthe molding chamber 22, in other words, on the inner wall surfacescorresponding to the surfaces which form the front and the back surfacesof the hollow resin molded board forming the sheathing board. However,it is desirable that it be performed on all of the upper, lower, rightand left inner surfaces of the molding chamber 22, as describedpreviously.

[0143] In FIG. 10, numerals 14 are heaters, which consist of a heatingmeans such as electrically heated heaters, and are installed as piping,by inserting four such heaters at equal intervals into the molding die10 above and below the molding chamber 22, corresponding to the meltingsection 21 a containing the lead in portion 11 spanning one fourth ofthe longitudinal direction of the whole molding die 10, for heating andmaintaining the temperature of the extruded materials 79, and forsustaining the fluidity of the extruded materials 79.

[0144] In addition, numerals 25 are cooling pipes, representing oneexample of cooling means to cool the annealing section 21 b of themolding chamber 22 of the molding die 10, to cool the extruded materials79 inside the molding chamber 22, by supplying the cooling pipe 25, atappropriate intervals in the pushing out direction of the moldingchamber 22, with a cooling liquid serving as a cooling medium, such aswater at room temperature, or water up to approximately between 70 and80° C., or oil. The pipes of these cooling pipes are installed aspiping, by inserting 8 such pipes at equal intervals in the molding die10 above and below the molding chamber 22, in the annealing section 21 baccounting for three fourths in the direction of the die outlet 23 ofthe molding die 10, to improve the annealing effect inside the moldingchamber 22 on the extruded materials 79. In addition, although thecooling pipes 25 may be installed by gradually narrowing the intervals,or, the cooling pipes 25 may be placed on the outer wall of the moldingdie 10, the construction is not restricted to this construction since itsuffices to cool the extruded materials 79 inside the molding chamber22.

[0145] (Core)

[0146] In FIG. 9 to FIG. 12, explanation is given on the core 40 usedwhen fabricating the sheathing board for use in a concrete form whereinhollow chambers are formed with a defined interval in the thickness. Thecore 40 is integrated with a base portion 44, having an arc shaped crosssection, and a guiding portion 15 provided with an inclined part 43which is inclined in the direction of the die outlet 23. The core 40consists of a molding guide portion 41, located in the melting portion21, formed by an approximately half portion situated on the side of theguiding portion 15, forming an overall shape of approximate comb teeth,with seven rod shaped members having a rectangular cross section, and atotal length of 800 mm and a width of 35 mm, and an extraction guideportion 42 located in the annealing portion 21 b, wherein a taper of onethousandth is formed in both the thickness and width, from this moldingguide portion 41 and in the direction of the die outlet.

[0147] The previously mentioned guiding portion has, in the lead-inchamber of the previously mentioned molding die, a total length ofbetween 70 and 95% of the total length in the direction of the width ofsaid lead in chamber. Moreover, it is preferably set at less than 70% ofthe height of said lead in portion, and one fourth of it, from theguiding portion 15 of core 40 in the direction of the front end dieoutlet 23, is located in the melting portion 21 a of the molding chamber22, and the remainder is located in the annealing portion 21 b.

[0148] In addition, the molding guide portion 41 of the previouslymentioned core 40, is formed linearly with a thickness of less than 45%of the height of the previously mentioned molding die, with the samethickness at the center of the molding die. The thickness of theextraction guide portion 42 is tapered in the direction of the front endof the die outlet 23.

[0149] Then, the previously mentioned core 40 is respectively alignedinto several columns parallel to the longitudinal direction of themolding chamber 22, in other words parallel to the direction of thepushing out, with an interval of four sevenths of the width of the core40.

[0150] The previously mentioned guiding portion 15 and core 40, have allthe outer surfaces affixed with sheets made of fluororesin such asteflon, with a thickness of between 0.1 and 0.5 mm. This guiding portion15 is placed inside the previously mentioned lead in chamber 13 with aheight of 18 mm and a width of 600 mm, approximately in the center,creating an interval of 28.5 mm each, in the direction of the width ofthe lead in chamber 13 and both ends in the direction of the width ofthe molding chamber. In addition, the back end side of the guidingportion 15 is placed so as to obtain an interval approximately parallelto the surface of the front end wall of the lead in portion 11, thisguiding portion 15 being fastened to the molding die 10 on the surfacebelow the lead-in chamber 13 with bolts 27 as shown in FIG. 12.Therefore, a gap is also formed between the upper surface of the guidingportion 15 and the upper surface of the lead-in chamber 13.

[0151] In addition, the thickness of the plates, and the width and theinterval of the guiding portion 15 and the core 40, may be suitablyselected according to the capacity of the molding chamber 22. In thepresent embodiment, 42 cores 40 having a square form cross section of10×10 mm are placed with a spacing of 3 mm.

[0152] If no core 40 is installed in the above mentioned molding die 10,an immaculate sheathing board is fabricated.

[0153] (Coarsely Crushing Means)

[0154] In FIG. 14 and FIG. 15, bearings 34 a for supporting the two endsof the shafts of three free pinch rollers 31 b, are respectively fixedto a bearing fixation frame 36, fixed pinch rollers 31 a are driven bythe gears 116 installed on each shaft, and gears 177 engaging with thesegears 116. On the shaft of one fixed pinch roller 31 a among the threefixed pinch rollers 31 a, an input shaft of a powder break 115 isconnected. The powder break is a so called electromagnetic break, andallows fine electrical adjustment of friction torque.

[0155] In addition, frames 114 are installed on the bearing fixationframe 36. Two block shaped guide members 119 with guiding grooves arerespectively installed on the surface of the w all of this frame 114,with the direction of the axial line of the guide member 119 orientedapproximately parallel to the up and down directions. Bearings 34 b forsupporting the two ends of the shafts of each of the three free pinchrollers 31 b are installed to move freely upwardly and downwardly alongthe guiding grooves of the previously mentioned guide member 119, andthe previously mentioned bearings 34b are respectively connected to thefront ends of rods of three air cylinders 118 installed on the uppersurface of the frames 114.

[0156] Therefore, under the operation of the cylinders 118, the threefree pinch rollers 31 b are respectively pressed against the fixed pinchrollers through a hollow resin molded board 29. The rotation of theshaft of one fixed pinch roller 31 a among the three fixed pinch rollers31 a is restricted by the powder break 115, and since the gear 116installed on the shaft of this fixed pinch roller 31 a is engaged withthe gears 116 and 116 installed on the shafts of the other two fixedpinch rollers 31 a and 31 b, through the shafts 117 and 117, the samerotation restriction force is applied on the three fixed pinch rollers31 a by the friction torque of the powder break 115.

[0157] In relation to the above, the friction torque for restricting therotation of the fixed pinch roller 31 a by the powder break 115 isadjusted by the thickness of the hollow resin molded board 29 to beformed.

[0158] Consequently, the friction torque of the powder break 115, is arestriction force against the force pushing out the hollow resin moldedboard 29, such that the extruded materials 79 inside the lead in portion11 of the molding die 10 are in a more uniform and more dense stateThese uniform and dense extruded materials 79 are pushed out by theforce of the extruded materials 79 generated by the extruder 70, proceedwhile resisting against the restriction force of the previouslymentioned coarsely crushing means 30, and are then cooled inside themolding chamber 22 and form the hollow resin molded board 29. Thishollow resin molded board 29 proceeds by resisting against therestriction force of the powder break 115, rotating the previouslymentioned fixed pinch rollers 31 a and the free pinch rollers 31 b.

[0159] The previously mentioned restriction force provides the extrudedmaterials 79 both inside the molding chamber 22 and inside the lead-inportion 11, through the hollow resin molded board 29, with a resistanceagainst the force applied by the extruder, which pushes out the extrudedmaterials 79 inside the molding chamber 22, and the entire extrudedmaterials 79 inside the molding chamber 22 become more uniform and ofhigher density. By applying a restriction force to the hollow resinmolded board 29, the density of the extruded materials 79 increases, andtherefore, the formation of air bubbles, foci and the likes isprevented. Consequently, a more uniform more dense and more lightweighthollow resin molded board is formed.

[0160] The sheathing board for use in a concrete form molded in theabove described way, may be used as a sheathing board, after eliminatingthe skin layer of the surface by, for example, a sanding treatment ofits surface, or without performing such processing, i.e. in the samestate as when it was molded.

[0161] A sheathing board made of resin to replace a sheathing board madeof plywood could be obtained, wherein the sheathing board of the presentinvention was obtained as described above, having characteristics thatare extremely close to those of natural wood. In addition, with theformation of hollow spaces, its relative density is approximately aslightweight as a sheathing board made of plywood, and processing, suchas cutting and drilling with manual tools, is relatively easy.

[0162] (Formation of Form (Mold))

[0163] The sheathing board 1 formed as described above, along with flaps51 and 52 or support columns, or other supporting materials, is combinedwith a separator 61 for opening a defined interval between the sheathingboards 1, and a form tightener 62, for tightening the sheathing boardsto prevent them from opening more than the specified spacing under thelateral pressure generated by the concrete, to form a concrete form 50.

[0164] As shown in FIG. 18, spacers 3 and 3 are mounted on the surfaceof one side, for example, at the opposite two edges of the sheathingboard 1 of the present invention. The mounting of spacers 3 and 3 allowsthe formation of specific concrete assemblies. For example, by opposingthe two sheathing boards 1 and 1 through the faces which are opposite tothe side where the spacers 3 and 3 are mounted, concrete is cast betweenthese boards 1 and 1, and a concrete wall having the thicknesscorresponding to this interval between the sheathing boards 1 and 1 isformed.

[0165] As shown in FIG. 19, a separator 61 serving as a connecting rodwhich connects between the sheathing boards 1 and 1, and stoppers 63 and63 such as standard washers, wood-concrete or plastic cones mounted onthe two ends of the previously mentioned separator 61, for controllingthe interval between the sheathing boards 1 and 1, and maintaining theinterval of the spacing between the sheathing boards 61, prevent theinterval of the space between the sheathing boards 1 and 1 fromnarrowing, and at the same time, by means of the form tighteners 62 and62, connected to one end of the previously mentioned stoppers 63 and 63,and piercing and protruding from the sheathing boards 1 and 1, nuts 64and 64, which screw into the threads formed at the other end of thepreviously mentioned tighteners 62 and 62, and the washers 6 5 and 65and the like, which are pressed in the direction of the sheathing boards1 and 1 by the tightening of the previously mentioned nuts 64 and 64, itis possible to press in the direction of the sheathing boards 1 and 1and stabilize the vertical flaps 51 and 51, as well as the horizontalflaps 52 and 52, positioned along the sheathing boards 1 and 1, and toprevent the deformation of the concrete form 50.

[0166] The previously mentioned separator 61 is installed in the spacemaintained between the sheathing boards 1 and 1, and is used as aconnecting rod connecting the sheathing board 1 and 1. Also, at theperiphery of both ends, a male thread is formed, at both ends of theseparators 51 and 51 stoppers 63 and 63 such as washers, wood-concreteor plastic cones are mounted and the stoppers 63 and 63 strike thesurface of the inner wall of the sheathing boards 1 and 1 to prevent theinterval between the sheathing boards 1 and 1 narrowing. As one example,in the present embodiment, standard plastic cones are used as thesestoppers 63 and 63.

[0167] The plastic cones used as the stoppers 63 and 63 consist of aflat topped cone shaped body wherein a nut or the like is buried and ascrew hole is formed which pierces the center, the end portion of thepreviously mentioned separator is screwed and inserted from the end atthe small diameter side up to the approximate center of this plasticcone, and the previously mentioned plastic cones are fixed at both endsof the separator.

[0168] The form tighteners 62 and 62 are mounted on the other end of theplastic cones which are screwed on both ends of the separator in theabove described way.

[0169] These form tighteners 62 and 62 are formed from iron poles havingthe same diameter as that of the previously mentioned separators 61 and61, and similarly to the previously mentioned separators, male screwthreads are formed at the peripheries of their two ends, and they arestabilized by screwing and inserting one end into the screw hole whichpierces the center of the plastic cones from the end on the largerdiameter side.

[0170] Then, the other ends of the previously mentioned form tightener62 and 62, while running through the washers 65 and 65, screw into thenuts 64 and 64. With the tightening of these nuts 64 and 64, thehorizontal flaps 52 and 52 abutting against the washers 65 and 65 arepressed in the direction of the sheathing boards 1 and 1. Thus, thesheathing boards 1 and 1 are fixed by the vertical flaps 51 and 51, andthe horizontal flaps 52 and 52 to form the concrete form 50.

[0171] In addition, the construction may be such that, as an alternativeto the washers through which the previously mentioned form tightenersrun, as shown in FIG. 20, curved washers 65′ and 65′ are mounted, andiron pipes are used as the horizontal flaps 52 and 52, fixed by thecurved surface of these curved washers 65′ and 65′.

[0172] In the embodiment shown in FIG. 21(A) and FIG. 21(B), the spacers3 and 3 are mounted along the two edges constituting the short edges ofthe sheathing board 1 formed to have a width of 600 mm, and a length of1,800 mm, and at the same time as aligning several layers of thissheathing board 1, the horizontal flap 52 is positioned with an intervalof approximately 750 mm, the vertical flap 51 is positioned with aninterval of approximately 300 mm, and the previously mentioned separator61 is installed with an interval in the vertical direction ofapproximately 750 mm, and with an interval in the horizontal directionof approximately 600 mm.

[0173] In addition, the sheathing board 1 of the present invention maybe positioned by taking the direction of the length as the direction ofthe height, as shown in FIG. 23(A) and FIG. 23(B), by mounting thespacers 3 and 3 along the two edges constituting the direction of thelength of the sheathing board, as shown in FIG. 22.

[0174] (Embodiment)

[0175] In the following, the embodiment of the present invention will beexplained.

[0176] (1) Example of Fabrication of the Sheathing Board

[0177] A sheathing board of the present invention was fabricated underthe conditions indicated below (in the table, immaculate means exampleof immaculate sheathing board).

[0178] Table 1 Example of Fabrication of Sheathing Board TABLE 1extruder diameter: 115 mm single shaft extruder clearance 0.2 mm (spacebetween the screw71 and the barrel 74) molding die 10 width: 730 mmHeight: 420 mm (vertical section in the direction of the width) deliveryamount hollow immaculate 115 kg/h 198 kg/h particle diameter meanparticle diameter less than 120 mesh of raw materials combinationthermoplastic resin PP 45 wt % actual relative amount 0.9 wood meal 55wt % water content 0.1 wt % actual relative amount 1.2˜1.4 productionhollow immaculate capacity approx. 15 m/h approx. 25 m/h

[0179] Under the above conditions, a sheathing board for use in aconcrete form was formed, by cutting a hollow board formed by extrusion,having a width of 600 mm, a thickness of 18 mm and a hollowness of 38.9%to a length of 1,800 mm.

[0180] This sheathing board has 42 hollow spaces formed, having arectangular cross section of 10 mm×10 mm formed in the direction of thelength of the sheathing board, in a width of 600 mm with an interval of3 mm, and its weight is approximately 13.3 kg.

[0181] In the case of an immaculate sheathing board, the width is 12 mm,and the weight is approximately 14.3 kg.

[0182] In addition, the calculation of the weight in the case of thehollow sheathing board, is as shown below:

[0183] In the event that a sheathing board having the same size isfabricated with only PP as raw materials, by taking approximately 0.9 asthe relative density of PP (ρ), the weight is

60×1.8×180×0.9=17.9 (kg),

[0184] and the sheathing board of the present invention is extremelylightweight, when compared to a sheathing board fabricated from only PPas raw materials;

[0185] in addition, when fabricating a sheathing board having the samesize from plywood, by taking 0.45 to 0.75 as the general relativedensity of plywood (ρ), the weight is

60×1.8×18×(0.45˜0.75)=8.7˜14.6 (kg),

[0186] and a lightweight sheathing board was obtained which comparesfavorably with a sheathing board made of plywood.

[0187] (2) Bending Strength Test

[0188] The bending strength of the sheathing board of the presentinvention, was evaluated under the conditions described below.

[0189] In addition, the sheathing board used as testing materials, withthe exception of the length, are identical to those fabricated in thepreviously mentioned example of fabrication.

[0190] test method: bissectional three point flexural test

[0191] test shape conditions: 600W×1000 L×18 T (immaculate: 12 T)

[0192] span: 900 mm

[0193] test speed: 5 mm/min

[0194] test room temperature: 20° C.

[0195] test room humidity: 60%

[0196] Under the above conditions, the results on the measurements ofthe bending strength of sheathing board of the present invention, areshown in Table 2. As it is clear from the Table 2, the sheathing boardof the present invention, has a bending strength of approximately twicethe standard value in the “concrete standards specifications(application)” established in Hei 8.(1998), and has an adequate strengthto be employed as a sheathing board for use in concrete form.

[0197] Table 2 Bending Strength Test TABLE 2 form of the presentapplication item units hollow immaculate standards bending kgf/cm² 328320 165 strength

[0198] (Mold Release Test)

[0199] The sheathing board of the present invention (without a moldrelease agent coat), and a sheathing board made of plywood coated with amold release agent, which were respectively not reused or reused threetimes were used to perform casting of concrete, the state of the surfaceof the sheathing board after mold release was visualized and inspected.The results are sh own in Table 3.

[0200] As is clear from Table 3, the sheathing board of the presentinvention has an excellent mold releasing property even after repeateduse, and it is shown that the board can endure repeated use, and has along lifespan.

[0201] Table 3 Mold Release Test TABLE 3 sheathing board of thesheathing board made of present application synthetic wood reused threereused three item non reused times non reused times state of the ◯ ◯ ◯ Δsurface

[0202] (Bending Strength Test on Regenerated Sheathing Board)

[0203] A non regenerated sheathing board of the present invention, and aregenerated sheathing board obtained by regenerating an already usedsheathing board by the method of the present invention, were taken asthe processing object of the bending strength test. The results of thetests performed on both sheathing boards are shown in the table 4. Inaddition, the testing conditions were identical to the previouslydescribed the bending test with non regenerated sheathing board(Table2). In the table, the sustain rate is expressed by the followingequation:

[0204] sustain rate (%)=(bending elasticity of the regenerated sheathingboard/bending elasticity of the regenerated sheathing board)×100

[0205] As shown in Table 4, when compared to the non regeneratedsheathing board, the bending strength (sustain rate) of the sheathingboard regenerated by the method of the present in vention decreases byonly approximately 2% and this decrease is almost unnoticeable, showingclearly that it has an adequate bending strength to be employed as aregenerated sheathing board for use in concrete form.

[0206] Table 4 Comparative Tests on the Bending Strength Between theRegenerated Sheathing Board and the Non Regenerated Sheathing Board.

[0207] (Application Test Example) TABLE 4 non item unit regeneratedarticle regenerated article bending kgf/cm² hollow immaculate hollowimmaculate strength 328 320 321 314 sustain % 100  98 rate

[0208] Using sheathing boards of the present invention (non regeneratedarticle and regenerated article) a concrete mold was assembled, andconcrete was cast inside this form, to fabricate a concrete wall havinga height of 7405 mm, a width of 9500 mm and a width of 1500 mm. Inaddition, the conditions for assembling the form are as shown in Table5.

[0209] Table 5 Application Conditions TABLE 5 No. of sheathing boardused approx. 65 interval between horizontal flaps  750 mm intervalbetween vertical flaps  300 mm interval between separators 1370 mm

[0210] The concrete form assembled with the above conditions, did notdisplay bowing, deformation, breakage or the like, due to the casting ofconcrete, and clearly shows that the sheathing board of the presentinvention has adequate strength to be employed as a sheathing board foruse in concrete form.

[0211] In addition, the surface after mold release of the concrete wallis even, moreover, at when released from the mold, incrustation ofconcrete on the surface of the sheathing board was hardly visible,clearly showing that the board has excellent characteristics as asheathing board.

[0212] With the construction of the present invention explained above,through a relatively simple method, without performing an operation toeliminate incrusted concrete and at a low cost, at the same time asrecycling synthetic wood materials turned into materials from an alreadyused sheathing board for use in concrete form having synthetic woodmaterials as raw materials, using this recycled resin materials and thelike as raw materials, for example, by refabricating a concrete form,the use of regenerated sheathing board made of resin is promoted, at thesame time as, a sheathing board made of low cost synthetic woodmaterials is provided, and the use of non recyclable form made ofplywood is reduced and allows an effective utilization of resources.

[0213] In addition, through the method of the present invention, thesheathing board for use in concrete form fabricated with recycledsynthetic wood materials as raw materials, is as light weight as asheathing board made of plywood, its workability is adequate and thehandling is convenient, and at the same time, it has an adequatestrength for use in concrete form, in addition, a form could be providedmade of resin which can be regenerated after use by retransforming intomaterials. Therefore, in this way, the usage of sheathing boards made ofplywood having natural wood as raw materials is reduced and an effectiveusage of the resources and the improvement of the natural environmentcan be achieved.

[0214] Now, that the invention has been described. Thus, the broadestclaims that follow are not directed to a machine that is configure in aspecific way. Instead, said broadest claims are intended to protect theheart or essence of this breakthrough invention.

[0215] This invention is clearly new and useful. Moreover, it was notobvious to those of ordinary skill in the art at the time it was made,in view of the prior art when considered as a whole.

[0216] Moreover, in view of the revolutionary nature of this invention,it is clearly a pioneering invention. As such, the claims that followare entitled to very broad interpretation so as to protect the heart ofthis invention, as a matter of law.

[0217] It will thus be seen that the objects set forth above, and thosemade apparent from the foregoing description, are efficiently attainedand since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatters contained in the foregoing description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

[0218] It is also to be understood that the following claims areintended to cover all of the generic and specific features of theinvention herein described, and all statements of the scope of theinvention which, as a matter of language, might be said to falltherebetween.

[0219] Explanation of Numerals

[0220]1 sheathing board used as concrete form

[0221]81 particles of sheathing board (after coarsely crushing step)

[0222]82 coated particles

[0223]83 granulated synthetic wood meal material

[0224]84 dust

[0225]100 sieve

[0226]102 dryer

[0227]110 crusher (coarsely crushing means)

[0228]120 cutter mill (fine crushing means)

[0229]121 cutter mill main body

[0230]123 charging port

[0231]124 cutter supporter

[0232]125 rotating knives

[0233]126 fixed knives

[0234]127 charging chamber

[0235]128 crushing chamber

[0236]129 screen

[0237]130 cleaning separator (means for the separation, classificationand size regulation)

[0238]131 fixed disk

[0239]132 supply charging port

[0240]133 fixed end plate

[0241]134 fixed pin

[0242]135 peripheral plate

[0243]141 mobile disk

[0244]142 horizontal rotation shaft

[0245]143 bearing

[0246]144 mobile pin

[0247]151 screen

[0248]152 discharge port

[0249]153 collection port

[0250]155 processing space

[0251]156 discharge space

[0252]157 blower

[0253]158 blower

[0254]161 motor

[0255]231 supply pipe

[0256]235 communicating pipe

[0257]236 piping

[0258]237 branch pipe

[0259]238 three way electromagnetic valve

[0260]239 discharge pipe

[0261]240 recovery tank

[0262]250 collection tank what is claimed is:

1. A method for recycling synthetic wood materials, comprising a stepwherein a sheathing board already used as a concrete form, consisting ofa synthetic wood material with a moisture content of less than 15 wt %,wherein between 20 and 75 wt % of cellulose crushed materials, such aswood meal with particle diameters of between 50 and 200 μm, and between25 and 80 wt % of thermoplastic resin molding materials, are mixed, isthe processing object, and this sheathing board is crushed into numerouscoated particles, and a step wherein a scraping impact force is appliedto each individual coated particle previously mentioned, concrete andother incrusted materials encrusted on the previously mentioned coatedparticles are peeled or separated, and at the same time as the syntheticwood materials constituting the coated particles and the incrustedmaterials are classified, the particles of the synthetic wood materialsare granulated and this granulated synthetic wood meal material whichhas been granulated is recycled.
 2. A sheathing board for use in aconcrete form having recycled synthetic wood material as raw materials,wherein synthetic wood materials recycled from a sheathing board madefrom synthetic wood materials which was already used as concrete form isused as raw materials, the synthetic wood materials has a moisturecontent of less than 15 wt %, and is a mixture of between 20 and 75 wt %of cellulose crushed materials, such as wood meal with particlediameters of between 50 and 200 μm, and between 25 and 80 wt % ofthermoplastic resin molding materials, numerous hollow chambers areformed inside its thickness, extended in a defined direction, at adefined interval, forming a hollowness of between 20 and 70 %, and atthe same time, the thickness of the walls delimiting the previouslymentioned hollow chambers is greater than 2 mm.
 3. A method forrecycling synthetic wood materials of claim 1 including a step whereinthe previously mentioned recycled granulated synthetic wood mealmaterial is sifted, and dust such as encrusted materials mixed among thegranulated synthetic wood meal materials is eliminated.
 4. A method forrecycling synthetic wood materials of claim 1 comprising a step whereinthe previously mentioned recycled granulated synthetic wood mealmaterial is dried to a moisture content of less than 0.1 wt %.
 5. Amethod for recycling synthetic wood materials of claim 3 comprising astep wherein the previously mentioned recycled granulated synthetic woodmeal material is dried to a moisture content of less than 0.1 wt %.
 6. Asheathing board for use in concrete form having recycled synthetic woodmaterials as raw materials, wherein synthetic wood materials recycledfrom a sheathing board made from synthetic wood material which wasalready used as a concrete form is used as raw materials, the syntheticwood material has a moisture content of less than 15 wt %, and is amixture of between 20 and 75 wt % of cellulose crushed materials, suchas wood meal with particle diameters of between 50 and 200 μm, andbetween 25 and 80 wt % of thermoplastic resin molding materials.